1. Field of the Invention
This invention generally relates to laser stealth technology, more specifically to an acrylic lens panel coated or infused with a filtering treatment for the absorption, diffusion, and dispersion of infrared laser light.
2. Background Information
The speed detection industry has evolved significantly over the past several years, beginning with the conventional radar gun and countermeasure radar detector progressing to the newer laser gun and more recent laser detector.
In the current art, conventional radar guns use the "first car" theory. Radar's wide beam allows operation of the radar gun from a moving or stationary vehicle. Target identification, however, is normally limited to the first car. This conventional radar emits microwave signals, detectable beyond line of sight by radar detection devices. This phenomenon allows radar detection devices to be an adequate countermeasure.
With the advancement of technology, however, has come the use and development of laser technology for speed detection. Laser technology in speed detection incorporates the lidar gun which uses a narrow beam from a stationary position. Laser operates on the parallax theory of two straight lines. Target identification is possible through sighting the beam on any vehicle within the operator's line of sight.
Visible light begins at approximately 400 namometers and ends at approximately 700 namometers. The lidar gun emits a laser frequency in the near infrared wavelength, the most common center frequency being approximately 905 namometers. The laser gun emits a short pulse of IR energy in a circular, narrow beam which is pointed at a vehicle's license plate because of the license plate's reflective properties. The distance to a target is then measured approximately 400 times per second.
Laser detection devices alone provide little or no advance warning while used in a lead vehicle. Most laser detection units alert you to laser only at the moment after the lidar gun has locked onto the auto's speed. Furthermore, many laser detection units, when tested, remained mute when the auto was locked into through a lidar gun from the rear of the vehicle.
Because a laser gun must "see" its' returning pulses, there has been experimentation in reducing the reflectivity of the auto. To date, strides in such experimentation were made only at the expense of the vehicle's function and appearance.
This young market has also attracted laser jamming products which do not fit the guidelines of conventional marketing prerequisites. Although many of these products have been tested with some success, they are not recommended due to price, legality, and general inconvenience.
There has also been experimentation and testing of actions and devices related to "flooding" the laser guns with large doses of infrared light. Current devices mount on the exterior of the vehicle near the vehicle's license plate such that when the laser gun is fired at the plate, the beam is flooded with infrared light, inhibiting reflection of the laser beam. These devices have met with limited success, primarily because they lack the sturdiness needed for mounting the device on the exterior of the vehicle.
Testing has also included turning a vehicle's driving lights on high, decreasing the reflective properties of the automobile. With the driving and bright lights illuminated, there was a significant decrease in the range and therefore the effectiveness of the lidar gun. Occasionally, however, the lidar gun was successful in locking into a speed even though an extensive amount of light was directed toward the gun. This method of inhibiting laser detection is not highly recommended however due to safety factors as drivers would be inclined to blind other drivers with high levels of light.
The physics of the laser gun demands different type countermeasures than those traditionally used for the radar gun. Applicant's invention addresses the need for an effective laser gun countermeasure without the negative side effects mentioned above. Applicant's invention was designed to eliminate the reflectivity of the vehicle license plate, thus reducing laser speed gun range. This method, used with a detector acts as a guard against laser speed measurement. The ability of Applicant's laser inhibitor to challenge the range of the laser gun makes Applicant's invention a solid countermeasure.